InRoads SS2 - existing dtm creation best practices

If the triangles were imported as breaklines, then they should be a feature(s). Can you just delete them or set them to DNC?

Thanks for the reply. The DTM has only triangles in it. No random points or anything else.

I had a similar situation on a project quite a few years ago. Before I joined the firm, someone had taken the the DTM over to Land Desktop and then brought it back. At this point, every triangle edge was a breakline and the surface was unworkable. I needed to punch holes in it to bring in new survey data and the edges of the holes were cutting triangle legs at random locations and sometimes those triangle were really bogus areas where they should have been trimmed.
Eventually, I went back to the original 3D photogrammetry cad files and in some cases, back to the original survey fieldbooks. Once I rebuild these into my DTM I had a file that was much easier to work with.
I would review the eight DTM's and see which ones seemed overwhelmed with random points or breaklines and see if I can thin or simplify them.
In your case, I would want to make sure the lidar data was thinned, as that can overwhelm a DTM. There is a thin random points tool that can be used.
Next I'd look at what files have triangles imported as breaklines. This creates issues as the extra processing to resolve every triangle leg as a breakline seems to really effect processing. If you have a 2D CADD file with linestrings that represent where breaklines should be of these DTM files, try changing all the breaklines into random points and then drape the linestrings using the vertices only setting to add simpler and far fewer breaklines back into the DTM.
Lastly, I don't understand how a DTM can contain only triangles and nothing else. In InRoads, a DTM contains features and features can be DNC, random, breaklines, interior and exterior. I've seen features with no visible name (one or more blank characters) and with unknown styles (style assigned with one XIN but now loaded with a different XIN) and these can make it impossible to display the features. But I've never seen an InRoads DTM with triangle but no features.
I've loaded GEOPAK TIN files and these seem to only load random points but I've been told if the TIN had Breaklines, the DTM would also have breakline.

Thanks Cop,

You are right on with your comments. Just to clarify, the triangles were imported from a microstation 3d file. They were assigned a feature (BREAKLINE) and a style (BRKLN). If you analyze the triangle (edit feature command) it is has 3 points.

You are correct the dtm is not usuable.

BTW - this is a non-feature based DTM. A breakline is a breakline, a random point is a random point.

I am trying to convince the client that we need to build the DTM using the breaklines and random points, along with incorporating the edits.

will know more next week.

Thanks,

The Drape 2D Graphics on now random points would probably work with this dataset. I have to sometimes work with AutoCAD files or people who used GEOPAK where all the linework for plan view graphics is 2D or in 2D files. So I have found it useful on multiple occasions.
When I ask for LandXML or 3D CAD linework, some people look at me like I have two heads.

The Drape 2D Graphics on now random points would probably work with this dataset. I have to sometimes work with AutoCAD files or people who used GEOPAK where all the linework for plan view graphics is 2D or in 2D files. So I have found it useful on multiple occasions.
When I ask for LandXML or 3D CAD linework, some people look at me like I have two heads.